# a,b,c = 12,2,3
# print (a+b)
# print (a-b)
# print (a*b)
# print (a/b)
# print (a%c)
# print (b**c)
# print (c//b)
#
#
# #关系运算符，返回结果为 true或false
# a,b,c = 12,2,3
# print(a==b)
# print(a!=b)
# print(a>b)
# print(a<b)
# print(a>=b)
# print(a<=b)
# #简单演示
# a,b,c=12,2,3
# c=a
# print(c)
# c+=a
# print(c)
# c**=b
# print(c)
# print(a and b)
# print(a or b)
# print(not a)
# a = 10;b = 20;list = [1,2,10,15]
# print(a in list)
# print(a not in list)
# print(b in list)
a = 10;b = 20;
print(a is b); print(a is not b);

while True:
    print(a)